This invention relates generally to orthodontic appliances for expanding the upper, or maxillary, jaw of a person. And more specifically the invention pertains to an expander connected to the jaw without using bands or crowns thus improving the appearance of a person's teeth when the present invention is installed for usage.
For many years, orthodontists have sought to correct the position of teeth for various reasons, including better chewing, better speech, hygiene, and appearance. Individual teeth can be rotated and translated into a new position. A tooth secures to the jaw with a periodontal ligament. Though extremely strong, the periodontal ligament can stretch as a tooth moves. Generally, a tooth is moved incrementally from an initial to a final position. Often the final position is along a defined arc.
Orthodontists have used many devices and therapies to move teeth. Common braces involve a wire secured to brackets or bands upon teeth. The brackets are adhered to the exterior face of a tooth or more recently to the interior face of a tooth. A wire then is placed upon the bracket and generally secured with small diameter elastic bands. The wire has an arcuate shape corresponding to the desired position of teeth. Wires are applied over time to the brackets with the wires becoming incrementally larger in diameter and hence more rigid. The rigidity of the wire gently orients a tooth to a new position. Brackets generally are used from the incisors rearward.
As teeth are to be moved, an orthodontist may have to create additional space along the jaw. Moving teeth rearward creates the space to accommodate teeth towards their final positions. An orthodontist applies bands to the molars and if needed, teeth forward of the molars. A band generally surrounds a tooth and is adhered to the tooth. The band has a fitting generally upon the exterior for securing the end of a wire used to establish a desired arc for the teeth. Bands also have sockets, generally horizontal, upon the exterior that cooperate with headgear. The headgear has interior rods that fit into the sockets and an outer bow joined to the interior rods. The outer bow connects to an adjustable strap that extends around the patient's neck. The strap provides a tension that is transferred into the bow and the interior rods to move the molars rearward thus opening space for other teeth to move. Teeth then move along the length of a jaw.
Additionally, an orthodontist may create space for teeth where a jaw is too narrow or more narrow than average. A jaw is widened by gently pushing apart molars outwards. Previously, molars were moved outwards using bands upon the rearmost molars connected to a threaded jack. The jack had a coaxial rod connected to a moving bar, or wing, and positioned by a threaded cylinder with keyholes. A patient would insert a key into the keyholes on a schedule prescribed by the orthodontist and turn the cylinder a prescribed rotation. Turning the cylinder urged the wings outwards and the jack against the molars to expand the jaw, generally the upper or maxillary jaw.
In recent years, orthodontia has developed mouth pieces that fit over teeth and direct teeth into new positions. The mouth pieces are translucent polymer material and fit upon existing teeth without the bands, wires, and brackets of previous methods. Invisalign® and other manufacturers provide mouth pieces, generally modeled in three dimensions by proprietary software for straightening teeth. The mouth pieces, similar to the prior art wires, gently move teeth incrementally over time. The mouth pieces can be worn during the daytime and are barely noticed by people other than a patient. An orthodontist prescribes the mouth pieces and the amount of tooth movement a given mouth piece induces. A mouth piece is generally held in place by friction between the mouth piece and the surface of the teeth. The mouth pieces perform well to align teeth along an arc, however the mouth pieces do not yet provide expansive lateral forces to widen a jaw.
Attempting to provide expansive lateral forces, the prior art connects an expansion device to a mouthpiece. The prior art utilizes vacuuming forming to connect an expansion device to a previously made mouthpiece. Further, an expansion device also joins to a mouthpiece as pelletized plastic or acrylic is placed intermittently upon the surface of a junction of the expansion device and a mouthpiece. The junction is then heated or chemically treated to make the pellets bond the expansion device to the mouthpiece.